Former Premier Silvio Berlusconi nearly collapsed during an emotional speech to political supporters Sunday, and aides rushed to the podium to keep him from falling.

The 70-year-old Italian media mogul later blamed exhaustion, and told reporters after flying by helicopter to one of his villas near Milan: "I feel well." But he said he would spend 24 hours at a Milan hospital as a precaution.

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"I collapsed from exhaustion, from the heat, from hard work, from antibiotics I am taking for a knee operation," a drawn-looking Berlusconi said before he was driven from the estate.

"They found something in the electrocardiogram, various extra systoles," he added, referring to contractions of the heart that force blood through the body.

The incident came as Berlusconi, leader of the conservative opposition, was about 40 minutes into a speech railing against Premier Romano Prodi's center-left government.

Berlusconi suddenly looked weak and started speaking slowly: "And now, excuse me, emotion is getting the better of me, and I ..." His voice trailed off, and he gripped the podium for support as he leaned back and aides rushed to his side.

About 30 minutes later, Berlusconi walked out of the hall in Montecatini Terme, a spa town in northern Italy, to a car. He looked pale as he waved to supporters of his Forza Italia party.

Berlusconi's personal physician, Umberto Scapagnini, told Sky TG24 that Berlusconi was examined by a cardiologist before he left the rally site.

Pounding the lectern and shouting at times during the speech, Berlusconi expressed anger over the center-left's victory in elections last April, which saw him lose power to Prodi and his allies.

His anger was fueled by an allegation in an Italian documentary that the conservative coalition tried to rig the election through a fraudulent count of thousands of blank ballots. A prosecutor has opened an investigation into the claim, which touched off a political storm.

Berlusconi angrily told the crowd Sunday that if there was fraud during the election, it was committed by the center-left.

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